create table admins (
    id integer primary key,
    admin_id bigint,
    channel_id bigint,
    channel_title varchar(255),
    unique (admin_id, channel_id)
);

create table announcements (
    id integer primary key,
    event_date date not null,
    channel_id bigint,
    post_text text,
    posted_by bigint,
    created_at timestamp default current_timestamp not null,
);
